1) Field of the Invention
The present invention relates to N-substituted-3-(substituted hydrazino)benzenesulfonamide derivatives, a preparation process thereof, and herbicidal compositions containing the derivatives as active ingredients.
2) Description of the Related Art
Numerous compounds have heretofore been proposed as herbicides. For example, U.S. Pat. Nos. 4,632,695, 4,664,695 and Japanese Patent Application Laid-Open (KOKAI) No. 129276/1987 disclose a wide variety of compounds, including N-substituted-3-substituted benzenesulfonamide derivatives containing NHC(CH.sub.3).dbd.CHCOCH.sub.3, NHC(CH.sub.3).dbd.CHCOOCH.sub.3, NHCH.sub.3, OCH.sub.2 CF.sub.3 or SCH.sub.2 CF.sub.3 on the 3-position and a pyrimidine ring or a 1,3,5-triazine ring on the nitrogen atom.
There have conventionally been strong demands for herbicides capable of exhibiting reliable herbicidal activity even at such low application dosages as bringing about the advantage of reducing the amount present in the environment, herbicides capable of exhibiting selectivity between crops and weeds irrespective of variations in environmental conditions, herbicides free from crop injury to the second crop in double cropping, etc. The present invention has been completed with a view toward meeting such demands.
The present inventors have found that compounds still unreported to date and having a substituted hydrazino group on the 3-position of benzenesulfonamide as opposed to the inclusion of NHC(CH.sub.3).dbd.CHCOCH.sub.3, NHC(CH.sub.3).dbd.CHCOOCH.sub.3, NHCH.sub.3, OCH.sub.2 CF.sub.3 or SCH.sub.2 CF.sub.3 on the 3-position of benzenesulfonamide in the compounds disclosed in EP-A-116518 and Japanese Patent Application Laid-Open (KOKAI) No. 129276/1987 have excellent herbicidal activity, leading to the completion of the present invention.